Tranny slow to shift up when cold

[Coast2Coast]

My 09 Tacoma did the same thing from the day it left the lot. It definitely shifted through all the gears though. The 99 runner does it too.

I know guys that went to 300K plus on 3rd gen 4runners that never had the time or patience to warm up longer than 30 seconds. With synthetic oils full of additives, and highly engineered new engines, the old warm up the engine before you go theory is dwindling IMO. The fact is that the engines are just very well put together and will last, even if you do treat them with what an everyday person would consider "abuse".

 

[thebitz1]

Glad I read this since my 99 Ltd is doing the same thing. Had it a week or so and I am going through the normal maint, etc that goes with a 1999 used car.

 

[jgue467]

Its normal

I read it in the user manual and FSM. Its programmed to delay the 2-3 shifts until a little warmth reaches the trans, mine does it every day for the first 1/2 mile (usually only the first 2-3 shift) or so then shifts as usual. Not sure what toyo's logic is on this but it is to be expected per their doco. Whew! :^)

 

[ZionXIX]

Despite being an old thread, the topic is applicable. I would like to believe that that my 4runner is refusing to shift into 3rd on cold startup due to an intentional safety feature requiring the transmission to warm up before shift into higher gears. I have the 1996 model SR5 2WD. From what I have been reading, there is no actively monitored trans temp sensor like the 99+ models. So does that "warm up" period still apply to my 96? How does the ECU know if it cant monitor the temp? I have been experiencing a delay in shifting from 2-3 on every cold startup. I currently live in a tropical climate that averages in the 80s all year round. Surely that fluid is warm enough. I dont recall noticing this shift delay when I first bought this vehicle 8 months ago. But I was also new to 4runners then. Its just really annoying having to drive uphill just to get out of your neighborhood and not have 3rd gear for the first 1/2 mile.

-z

 

[JayRolla]

Despite being an old thread, the topic is applicable. I would like to believe that that my 4runner is refusing to shift into 3rd on cold startup due to an intentional safety feature requiring the transmission to warm up before shift into higher gears. I have the 1996 model SR5 2WD. From what I have been reading, there is no actively monitored trans temp sensor like the 99+ models. So does that "warm up" period still apply to my 96? How does the ECU know if it cant monitor the temp? I have been experiencing a delay in shifting from 2-3 on every cold startup. I currently live in a tropical climate that averages in the 80s all year round. Surely that fluid is warm enough. I dont recall noticing this shift delay when I first bought this vehicle 8 months ago. But I was also new to 4runners then. Its just really annoying having to drive uphill just to get out of your neighborhood and not have 3rd gear for the first 1/2 mile.

-z

It goes off water temp. I start my 96 up about 5 minutes before I go in the mornings and it never slow shifts. It's normal just like everyone has said.

 

[jeremyc74]

There's a misunderstanding going on here about why the transmission delays shifts when it's cold. It's not to protect the transmission, it's to help get the catalytic converters up to temperature so the system goes into closed loop faster. There is an emission regulation requirement for cold starts that they have to meet, and keeping the RPMs up helps with it.

If you're experiencing the delayed shifts longer than usual, it's probably an issue with the thermostat sticking open, not something wrong with the transmission.

 

[ZionXIX]

There's a misunderstanding going on here about why the transmission delays shifts when it's cold. It's not to protect the transmission, it's to help get the catalytic converters up to temperature so the system goes into closed loop faster. There is an emission regulation requirement for cold starts that they have to meet, and keeping the RPMs up helps with it.

If you're experiencing the delayed shifts longer than usual, it's probably an issue with the thermostat sticking open, not something wrong with the transmission.

Thanks for the clarification. What would be considered "longer than normal"? If I don't let it warm up, it can take up to 1/2 a mile or so before I feel that 3rd gear engage. A lot of these Island vehicles don't even have thermostats and my 4runner runs on the cold side most of the time so I'm fairly certain that I don't have one. I bought an OEM thermostat but have yet to install it. Perhaps that will shorten my shift delay problem.

 

[JayRolla]

Thanks for the clarification. What would be considered "longer than normal"? If I don't let it warm up, it can take up to 1/2 a mile or so before I feel that 3rd gear engage. A lot of these Island vehicles don't even have thermostats and my 4runner runs on the cold side most of the time so I'm fairly certain that I don't have one. I bought an OEM thermostat but have yet to install it. Perhaps that will shorten my shift delay problem.

Mine does this since I've owned it. Only when cold. Summer it shifts slow maybe for the first up shift.

 

[jeremyc74]

Thanks for the clarification. What would be considered "longer than normal"? If I don't let it warm up, it can take up to 1/2 a mile or so before I feel that 3rd gear engage. A lot of these Island vehicles don't even have thermostats and my 4runner runs on the cold side most of the time so I'm fairly certain that I don't have one. I bought an OEM thermostat but have yet to install it. Perhaps that will shorten my shift delay problem.

It would be hard to put a number on it, because it's going to vary with ambient temperature, but in the tropics you should barely notice it at all.

If you don't have a thermostat, I'd say that would definitely cause it to take longer. The ECU is looking for a certain water temperature before it thinks things are warmed up and normal.